Background: Human body contains many kinds of different type of endothelial cells (EC). However, cellular difference of their angiogenic potential has been hardly understood. We compared in vitro angiogenic potential between arterial EC and venous EC and investigated its underlying molecular mechanisms.
Method: Used human aortic endothelial cells (HAEC) which was indicated from arterial EC and human umbilical vein endothelial cells (HUVEC) indicated from venous EC. To explore angiogenic potential in detail, we adopted a novel 3D microfluidic angiogenesis assay system, which closely mimic in vivo angiogenesis.
Results: In 3D microfluidic angiogenesis assay system, HAEC demonstrated stronger angiogenic potential compared to HUVEC. HAEC maintained its profound angiogenic property under different biophysical conditions. In mRNA microarray sorted on up- regulated or down-regulated genes, HAEC demonstrated significantly higher expression of gastrulation brain homeobox 2 (GBX2), fibroblast grow factor 2 (FGF2), FGF5 and collagen 8a1. Angiogenesis-related protein assay revealed that HAEC has higher secretion of endogenous FGF2 than HUVEC. HAEC has only up-regulated FGF2 and FGF5 in this part of FGF family. Furthermore, FGF5 expression under vascular endothelial growth factor-A (VEGF-A) stimulation was higher in HAEC compared to HUVEC although VEGF-A augmented FGF5 expression in both HAEC and HUVEC. Those data suggested that FGF5 expression in both HAEC and HUVEC is partially dependent to VEGF-A stimulate. HUVEC and HAEC reduced vascular density after FGF2 and FGF5 siRNA treat.
Conclusion: HAEC has stronger angiogenic potential than HUVEC through up-regulation of endogenous FGF2 and FGF5 expression